Python - typing 模块 —— 常用类型提示

# name 参数类型为 str
def greeting(name: str) :
    return "hello"

# 多个参数，参数类型均不同
def add(a: int, string: str, f: float, b: bool or str):
    print(a, string, f, b)

# 函数返回值指定为字符串
def greeting(name: str) -> str:
    return "hello"

from typing import Tuple, List, Dict


# 返回一个 Tuple 类型的数据，第一个元素是 List，第二个元素是 Tuple，第三个元素是 Dict，第四个元素可以是字符串或布尔
def add(a: int, string: str, f: float, b: bool or str) -> Tuple[List, Tuple, Dict, str or bool]:
    list1 = list(range(a))
    tup = (string, string, string)
    d = {"a": f}
    bl = b
    return list1, tup, d, bl


# 不 warn 的调用写法
print(add(1, "2", 123, True))


# 输出结果
([0], ('2', '2', '2'), {'a': 123}, True)

def test(a: list, b: dict, c: set, d: tuple):
    print(a, b, c, d)

a: List[int, str] = [1, "2"]
b: Set[int, str] = {1, 2, 3}

Traceback (most recent call last):
  File "/Users/polo/Documents/pylearn/第二章：基础/13_typing.py", line 36, in <module>
    a: List[int, str] = [1, "2"]
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/typing.py", line 261, in inner
    return func(*args, **kwds)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/typing.py", line 683, in __getitem__
    _check_generic(self, params)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/typing.py", line 215, in _check_generic
    raise TypeError(f"Too {'many' if alen > elen else 'few'} parameters for {cls};"
TypeError: Too many parameters for typing.List; actual 2, expected 1

d: Tuple[int, str] = (1, "2")
print(d)


# 输出结果
(1, '2')

d: Tuple[int, str] = (1, "2", "2") 

d: Tuple[int, ...] = (1, 2, 3)
d: Tuple[Dict[str, str], ...] = ({"name": "poloyy"}, {"age": "33"})